1. Field of the Invention
The present invention relates to a control device for make break switches, such as breakers, installed in, for example, transforming stations and switchyards.
2. Discussion of Background
As an operating force for a control device for breakers, as a make break switch, a spring force is practically used. FIGS. 70 through 73 illustrate a conventional control device for breakers, which is disclosed in Japanese Unexamined Patent Publication JP-A-63-304542. FIG. 70 is a perspective view illustrating a structure of the control device for the breaker. FIG. 71 illustrates an important portion of the structure of the control device for the breaker, wherein the breaker is in a state of closing a circuit, and breaking torsion bars and closing torsion bars are prestressed.
FIG. 72 illustrates an important portion of the structure of the control device for the breaker, wherein the breaker is in a state of opening the circuit, an opening torsion bar is released, and a closing torsion bar is prestressed. FIG. 73 illustrates an important portion of the structure of the control device for the breaker, wherein the breaker is in a state of closing the circuit, the opening torsion bar is prestressed, and the closing torsion bar is released.
In these figures, numerical reference 1 designates a case; numerical reference 24 designates a cylinder, fixed to the case 1; and numerical references 26 and 27 respectively designate rotatable levers, which are engaged with pins (not shown), formed on end surfaces of the cylinder 24. Numerical references 28 and 34 designate the opening torsion bars; and numerical references 29 and 35 designate the closing torsion bars. The opening torsion bar 28 is fixed to the case 1 at one end and also fixed to the lever 26 at the other end. The opening torsion bar 34 is fixed to a rotational shaft 32 at one end as illustrated in FIG. 71, and fixed to the lever 26 at the other end.
The closing torsion bar 29 is fixed to the case 1 at one end and fixed to the lever 27 at the other end. The closing torsion bar 35 is fixed to a rotational shaft 33 at one end, as illustrated in FIG. 71, and fixed to the lever 27 at the other end. Although, details will be described in this specification, because the closing torsion bars 29 and 35 are released when the opening torsion bars 28 and 34 are prestressed, prestressing energy of the closing torsion bars 29 and 35 is larger than prestressing energy of the opening torsion bars 28 and 34.
Numerical reference 37 designates a making lever fixed to the rotational shaft 33, wherein the making lever is applied with a counterclockwise rotational force in FIG. 71 by the closing torsion bars 29 and 35. Numerical reference 2 designates a camshaft, supported by the case 1; numerical reference 3 designates a cam, mounted on the camshaft; numerical reference 13 designates a second pin, formed in the cam; and numerical reference 14 designates a making latch, engaged with the second pin 13. Numerical reference 15 designates a making trigger, engaged with the making latch 14; and numerical reference 16 designates a making electromagnet having a plunger 17.
Numerical reference 38 designates a rotational shaft, supported by the case 1, whereby the rotational shaft is driven by a motor (not shown) in a counterclockwise direction. Numerical reference 39 designates a pinion, fixed to the rotational shaft 38; and numerical reference 40 designates a gear, engaged with the pinion 39 and fixed to the camshaft 2, wherein teeth are partly removed so that the engagement with the pinion 39 is released when the closing torsion bars 29 and 35 are prestressed. Numerical reference 41 designates a link, connecting the making lever 37 with the gear 40.
Numerical reference 36 designates a breaking lever, fixed to the rotational shaft 32, wherein the breaking lever is applied with a rotational force in a counterclockwise direction by the opening torsion bars 28 and 34. Numerical references 8 and 9 respectively designate a first pin and a rotor, both of which are located in the breaking lever 36. Numerical reference 18 designates a releasing latch, which is engaged with the first pin 8 and applied with rotational force in a clockwise direction by a spring 43.
Numerical reference 19 designates a releasing trigger, engaged with the releasing latch 18. Numerical reference 20 designates a releasing electromagnet having a plunger 21. Numerical reference 22 designates a movable contact of the breaker, wherein the movable contact is connected to the breaking lever 36 through a linkage mechanism 23. Numerical reference 42 designates a buffer, connected to the breaking lever 36 to relax an impact applied at time of opening and closing the movable contact 22.
In the next, an operation of opening the circuit will be described. The breaking lever 36 is constantly applied with a rotational force in a counterclockwise direction by the opening torsion bars 28 and 34, and the rotational force is retained by the releasing latch 18 and the releasing trigger 19. When the releasing electromagnet 20 is excited in this state, the plunger 21 is moved in a rightward direction; the releasing trigger 19 is rotated in a clockwise direction; and the releasing latch 18 is rotated in a counterclockwise direction by a counter force, applied from the first pin 8. When the releasing latch 18 is released from the first pin 8, the breaking lever 36 is rotated in a counterclockwise direction, and the movable contact 22 is driven in a direction of opening the circuit. A state that the operation of opening the circuit is completed is illustrated in FIG. 72.
An operation of closing the circuit will be described. In FIG. 72, the cam 3 is connected to the making lever 37 through the camshaft 2, the gear 40, and the linkage 41, wherein a rotational force in a clockwise direction is applied by the closing torsion bars 29 and 35. The rotational force is retained by the making latch 14 and the making trigger 15.
When the making electromagnet 16 is excited to drive the plunger 17 in the rightward direction, the making trigger 15 is rotated in the clockwise direction; and the making latch 14 is rotated in the counterclockwise direction by a counterforce applied from the second pin 13. Because the making latch 14 is released from the second pin 13 to rotate the cam 3 in the clockwise direction so that the rotor 9 located in the breaking lever 36 is pushed up, the breaking lever 36 twists the opening torsion bars 28 and 34 in the clockwise direction.
When the breaking lever 36 is rotated by a predetermined angle and the movable contact 22 is driven in the direction of closing the circuit, the releasing latch 18 is engaged with the first pin 8, and the releasing trigger 19 is engaged with the releasing latch 18. The cam 3 is rotated while holding the breaking lever 36 through the rotor 9 until an engagement between the releasing latch 18 and the first pin 8 and an engagement between the releasing trigger 19 and the releasing latch 18 are stabilized. Thereafter, the cam 3 is disconnected from the rotor 9. FIG. 73 illustrates a state that the operation of closing the circuit is completed and the first pin 8 is held by the releasing latch 18. The control device for breaker should be operated to reopen the circuit immediately after closing the circuit, wherein the operation of reopening the circuit is to open the circuit from the state illustrated in FIG. 73.
The closing torsion bars 29 and 35 are prestressed as follows. As illustrated in FIG. 73, immediately after completing to close the circuit, the closing torsion bars 29 and 35 are in a releasing state. By rotating the pinion 39 in the counterclockwise direction by the motor (not shown), the gear 40 is rotated in the clockwise direction, and the closing torsion bars 29 and 35 are prestressed through the linkage 41, the making lever 37, and the rotational shaft 33.
After exceeding a dead point where a direction of pulling the linkage 41 crosses a center of the camshaft 2, the camshaft 2 is applied with a rotational force in the clockwise direction through the linkage 41 by a force of the closing torsion bars 29 and 35. Simultaneously, since the teeth of the gear 40 are partly removed, the engagement between the pinion 39 and the gear 40 is released. The making latch 14 is engaged with the second pin 13, and the rotational force of the gear 40 in the clockwise direction, caused by the force of the closing torsion bars 29 and 35, is retained, whereby the prestressing operation is completed. Thereafter, the state illustrated in FIG. 71 is realized.
In the above-mentioned conventional control device for breaker, the breaking lever 36 is rotated in the clockwise direction by the cam 3, illustrated in FIG. 72, and the movable contact 22 is driven in the direction of closing the circuit. When the breaking lever 36 is rotated by the predetermined angle, the releasing latch 18 is engaged with the first pin 8, and the releasing trigger 19 is engaged with the releasing latch 18. The cam 3 is further rotated and holds the breaking lever 36 through the rotor 9 until the engagement between the releasing latch 18 and the first pin 8, and the engagement between the releasing trigger 19 and the releasing latch 18 are stabilized. Thereafter, the contact between the cam and the rotor 9 is released.
Thus, a reactive motion is apt to occur when the releasing latch 18 and the first pin 8 are engaged, and the releasing trigger 19 and the releasing latch 18 are engaged, and further the cam 3 should hold the engagement while the reactive motion is ceased and the engagements are stabilized. Since the operation of opening the circuit cannot be performed while the cam 3 holds the breaking lever 36, there is a problem that this feature prevents a time for starting next operation of opening the circuit from being sufficiently shortened.
It is an object of the present invention to solve the above-mentioned problems inherent in the conventional technique and to provide a control device for make break switches, which can reduce the time from closing of a circuit to opening the circuit.
Another object of the present invention is to provide a control device for breakers, wherein the number of the parts of the control device is reduced, mechanical impact is prevented, and the size of the control device is reduced.
According to the present invention, to achieve the above-mentioned problems, there is provided a control device for a make break switch comprising: a first breaking lever, supported by a supporting structural member so as to be rotatable and connected to a contact; a prestressing means for opening a circuit urging the first breaking lever so that the first breaking lever is rotated in a predetermined direction; a linkage having first and second links and a connecting portion connecting the first linkage with the second linkage so as to be collapsible and connected to the first breaking lever through the first link; a second breaking lever, supported by the supporting structural member so as to be rotatable and connected to the second link; a making lever, supported by the supporting structural member so as to be rotatable and connected to and disconnected from the second breaking lever; a prestressing means for closing the circuit, which urges the making lever so as to be rotated in a direction adverse to the predetermined direction; a making latch for securing the making lever; a guide having a guiding surface for guiding a connecting portion while keeping a contact with the connecting portion and supported by the supporting structural member so that the guide is movable; a first releasing latch for securing the guide; and a second releasing latch for securing the second breaking lever and interlocked with the guide, wherein when an engagement of the guide by the first releasing latch is released, the guide is pushed by the connecting portion and moved, the engagement between the second releasing latch, interlocked with the guide, and the second breaking lever is released, and the first breaking lever is rotated and driven in a predetermined direction by releasing the prestressing means for opening the circuit to open the contact, the guide is engaged again with the first releasing latch after the first breaking lever is rotated by a predetermined angle in a predetermined direction, the second breaking lever is rotated and driven in a direction adverse to the predetermined direction through the making lever when the prestressing means for closing the circuit is released by disengagement between the making latch and the making trigger, the connecting portion is guided by a guiding surface of the guide, engaged with the first releasing latch, to close the contact by rotating the first breaking lever in the direction adverse to the predetermined direction, simultaneously the prestressing means for opening the circuit is prestressed, and a prestressed state of the prestressing means for opening the circuit and a state of closing the contact are maintained by engagement between the second breaking lever and the second releasing latch.
Because the guide is engaged with the first releasing latch when the first breaking lever is rotated by the predetermined angle in the predetermined direction at time of opening the contact, namely, the guide is engaged with the first releasing latch before next operation of closing the circuit, the operation of opening the circuit can be immediately started before the guide is engaged with the first releasing latch when the circuit is completely closed.
Further, an aspect is that a circuit opening motion preventing member, stopping a motion of a first releasing latch during an operation of closing a circuit by a make break contact in association with a rotation of a making lever or a first breaking lever, is located.
By preventing a release of an engagement of a guide upon an erroneous operation of a first releasing latch in course of a close of the circuit, the circuit opening motion preventing member prevents the release, whereby it is possible to avoid a generation of a large impact caused by a collision between the first breaking lever, which is rotated in a predetermined direction by a prestressing means for opening the circuit when the engagement of the guide is released and a support by the connecting portion is lost in the course of the closing operation, and the second breaking lever, rotated in a direction adverse to the predetermined direction by the making lever in course of the closing operation.
Another aspect is that, by locating a releasing trigger so as to be rotatable in a supporting structural member and rotating the releasing trigger, an engagement of a guide by a first releasing latch is released, and a circuit opening motion preventing member moves along with a rotation of a making lever or a first breaking lever to stop a rotation of the releasing trigger in a course of the closing operation of a make break contact. In use of the simple structure, it is possible to avoid a release of the engagement of the guide by the first releasing latch as a result of a rotation of the first releasing latch in the course of the closing operation.
Another aspect is that a circuit closing motion preventing means is located to stop an operation of a making latch along with a rotation of a first breaking lever in a state that a make break contact is closed. By making a circuit closing motion preventing means mechanically interlocked with a rotation of the first breaking lever, it is possible to stop an operation of the making latch. Accordingly, when both of a prestressing means for opening the circuit and a prestressing means for closing the circuit are prestressed, it is possible to prevent a large impact, caused by a collision of a making lever and a second breaking lever upon a release of an engagement of the making lever by the making latch, from being generated.
Another aspect is that a making trigger is located in a supporting structural member so as to be rotatable, an engagement of a making lever by a making latch is released by a rotation of the making trigger, a circuit making and opening motion preventing member is moved along with a rotation of a first breaking lever, and a rotation of the making trigger is stopped in a state that a make break contact is closed.
By such simple structure, it is possible to prevent a release of the engagement of the making lever by the making trigger upon a rotation of the making trigger in the state that the make break contact is closed.
Another aspect is that a circuit opening motion preventing member for stopping an operation of a first releasing latch along with a rotation of a making lever or a first breaking lever during a closing operation of a make break contact and a circuit closing motion preventing means for stopping an operation of the making latch along with a rotation of a first breaking lever in a state that the make break contact is closed. By preventing an erroneous release of an engagement of a guide upon an operation of the first releasing latch, it is possible to prevent a danger that a large impact is generated by a collision of the first breaking lever, rotated in a predetermined direction by the prestressing means for opening the circuit when the engagement of the guide is released and a support of the connecting portion is canceled, and a second breaking lever, which is rotated in a direction adverse to the predetermined direction by the making lever, during the operation of closing the circuit.
Another aspect is that, it is possible to stop an operation of a making latch by a mechanical interlock between a rotation of the first breaking lever and a circuit closing motion preventing member. Accordingly, when both of a prestressing means for opening a circuit and a prestressing means for closing the circuit are prestressed, it is possible to prevent a large impact, caused by a collision between the making lever, of which engagement is released from a making latch, and a second breaking lever.
Another aspect is that a releasing trigger and a making trigger are located in a supporting structural member so as to be rotatable. By rotating the releasing trigger, an engagement of a guide by a first releasing latch is released. Simultaneously, by rotating a making trigger, an engagement of a making lever by the making trigger is released, a circuit opening motion preventing member moves along with a rotation of the making lever or a first breaking lever to stop a rotation of the releasing trigger during a closing operation of a make break contact, and a circuit closing motion preventing member moves along with a rotation of the first breaking lever to stop a rotation of the making trigger in a state that the make break contact is closed.
By such simple structure, it is possible to prevent a release of the engagement of the guide by the first releasing latch upon a rotation of the first releasing latch during the closing operation and a release of the engagement of the making lever by the making trigger upon a rotation of the making trigger in the state that the make break contact is closed, whereby a large impact can be prevented from occurring.
Another aspect is that a stopper is further located for receiving a releasing force of a prestressing means for closing a circuit when an engagement of a guide by a first releasing latch is canceled when the prestressing means for closing the circuit is released or the prestressing means for closing the circuit is in a released state.
Even though a limiter is located, it is possible to open the circuit immediately after completing to close the circuit. Therefore, when the circuit is opened immediately after completing to close the circuit, it is possible to prevent an excessive impact, caused by a collision, from occurring by receiving the releasing force of the prestressing means for closing the circuit, left after an operation of closing the circuit, by the stopper.
Another aspect is that a prestressing means for opening a circuit and a prestressing means for closing the circuit are torsion bars. In use of the torsion bars, efficiency of energy is improved, and concentration of stress is avoided.
Another aspect is that a prestressing means for opening a circuit and a prestressing means for closing the circuit are coil springs. In use of the coil springs, the prestressing means becomes compact.
Another aspect is that a first breaking lever and a second breaking lever are commonly supported by a supporting shaft, located in a supporting structural member so as to be rotatable. Because it is unnecessary to individually support the breaking levers, the number of components is reduced, and a structure is simplified.
Another aspect is that a second breaking lever and a making lever are commonly supported by a supporting shaft, located in a supporting structural member, so as to be rotatable. Because it is unnecessary to individually support the second breaking lever and the making lever, the number of components is reduced, and a structure is simplified.
Another aspect is that a first breaking lever, a second breaking lever, and a making lever are commonly supported by a supporting shaft, located in a supporting structural member, so as to be rotatable. Because it is unnecessary to individually support the first breaking lever, the second breaking lever, and the making lever, the number of components is reduced, and a structure is simplified.
Another aspect is that a guide and a second releasing latch are commonly supported by a supporting shaft, located in a supporting structural member, so as to be rotatable. Because it is unnecessary to individually support the second releasing latch and the making lever, the number of components is reduced, and a structure is simplified.
Another aspect is that a first breaking lever and a second breaking lever are commonly supported by a supporting shaft, located in a supporting structural member, so as to be rotatable, and a guiding surface of a guide forms an arch, and the center of the arch of an arch surface is positioned in a middle of the supporting shaft when the guide is engaged with the first releasing latch. Therefore, it is possible to control a locus of movement of a connecting portion by a simple structure.
Another aspect is that a first breaking lever and a second breaking lever are commonly supported by a supporting shaft, located in a supporting structural member, so as to be rotatable, and a guiding surface of a guide is flat, whereby the guiding surface is easily processed, and a torque of a prestressing means for closing a circuit, transmitted to a first breaking lever at a time of starting to close the circuit or at a time of completing to close the circuit, is increased.
Another aspect is that a rotor of a linkage, being in contact with a guiding surface of a guide and guided by its rotation, is located in a connecting portion, whereby a frictional resistance, caused when the connecting portion is guided by the guide, is reduced, and a prestressed energy of a prestressing means for closing a circuit is effectively transferred to a first breaking lever at a time of closing a contact and prestressing a prestressing means for opening the circuit.
Another aspect is that a prestressing means for closing a circuit is prestressed by a prestressing device, which drives a making lever by a cam, driven by a motor, whereby a shape of the cam is determined to control a load of a torque of the motor at a time of prestressing the prestressing means for closing the circuit, and a maximum torque, applied to components of a prestressing device, is reduced.
Another aspect is that a prestressing device has a breaking member, which breaks a cam by a sliding motion on the cam so as to be elastically deformed, whereby the cam, rotating by inertia, is rapidly stopped by the break.
Another aspect is that a cam and a making latch are commonly located in a shaft so as to be rotatable, a prestressing means for closing a circuit is held to be in a prestressing state by an engagement between the making latch and the making lever, and the prestressing means for closing the circuit is released by canceling an engagement between the making latch and the making lever, whereby it is unnecessary to prepare a shaft for supporting the making latch, and the number of components is reduced.
Another aspect is that a make break switch is a breaker, wherein a control device is suitable for a breaker.